Process for recovering waste lime.



J. G. JONES. PROGESS FOR REOOVERING WASTE LIME.

APPLICATION FILED JUNE 3, 1907.

in HIV I H H, .H

aJm

0 w CEEEEC.m

EZZZZZEZZSZZZ2222i m CLEECEECE E EE LECEECCCCEECCCEidM tJJJJJDJJJJJJJJJJJJJJJJJJJJJJ1 m ZZZZZZZZiiiii MN P LEEEEZZEzzzfifi dJUDJIJDJDDJJJJJJJ33333333] W'RN EEZEZZZZZZE2225:

R m E W JOHN G. JoNEs, or GARTHAG-E, NEW YORK.

PROCESS FOR RECOVERING WASTE LIME.

Specification of Letters Patent.

Patented March 30, 1909.

Application filed June 3, 1907. Serial No. 377,033.

To all whom it may concern:

Be it known that 1, JOHN G. JoNEs, a citizen of the United States,residing at Carthage, in the county of Jefferson and State of New York,have invented certain new and useful Improvements in Processes forRecovering vVaste Lime; and I do hereby declarethe following to be afull, clear, and exact description of the invention, such as will enableothers skilled in the art to which it appertains to make and use same,reference being had to the accompanying drawings, and to the letters andfigures of reference marked thereon, which form a part of thisspecification.

This invention relates to new and useful processes of purifying andrevivifying spent -or waste lime, and consists, first, in separating theimpurities from the lime in its carbonate state, after which the lime isrelieved of a large percentage of its moisture and, in a plastic state,placed in a drying, chamber and subjected to air highly heated by wasteCO as issuing from a rotary kiln and given u from the waste carbonate oflime being ca cined in the kiln.

More specifically the invention comprises a method of recovering spentlimes and, in carrying out the steps of the process, the Waste lime isremoved of its impurities preferably by centrifugal action, after whichthe resultin pure carbonate of lime in a semi-liquid orm is pumped intoan agitator storage tank where it is thoroughly agitated and not allowedto settle. From the agitator, the lime in its semi-liquid form-is pumpedinto a filter press, of any suitable design, and excess of waterfiltered off under pressure. The lime being formed into cakes in therecesses between the filter plates is removed from the filter press andtransferred into a drying kiln where the cakes are thoroughly driedafter which the cakes are broken up into small pieces in a suitablecrusher and the ieces of a suitable size elevated into storage ins fromwhich the lime is fed into a slowly revolving rotary kiln, the latterbeing lined throughout with fire resistin brick with part of the brickextended for t e purpose of a itating the ieces of lime as they passslow y through t e rotar kiln. Heat at a high temperature is intro ucedinto the 1 discharge end of the rotary kiln, raisin the temperature ofthe fire brick lining o the kiln to an incandescent point and, as the bythe lime material may be pieces of lime cake are fed into the kiln, theytravel slowly forward and absorb the heat both from the highly heatedbrick lining and the burning gases produced in a gas producer or otherheat producing apparatus, whereradually raised-in temperature until itis ma e to give off its CO in the burning zone and is reduced to'theoxid state, in which state it is dis charged from the kiln and removedto a stor age tank for commercial use.

I illustrate an apparatus whereby the steps of m process may be carriedout and, in which il ustration, I have shou'nin Figures 1 and 2diagrammatic views, which talgen together illustrate the completeapparatus.

Reference now being had to the details of the drawings by letters and fiures, A designates a separator which may e of any suitable design forseparating the impurities from the lime material, preferably bycontrifugal action but any other means, of course, may be employed ifdesired.

B designates a pump for pumping the lime material, free from itsimpurities, from the separator A through the pipe C and thence throughthe pipe D into the agitator tank E.

F designates a, pump which communicates by means of the be F with theagitator tank E, and provirfe for the purpose of drawing the limematerial in a semi-liquid form from the agitator tank to a filter pressG, of

any suitab e design, in which the excess of water is filtered off underpressure, the lime being formed into cakes in the recesses between the,filter plates. The cakes are then removed from the filter .ress, placedupon a car H traveling u on t e track I and conveyedv to the tree J,which runs at right angles to the track I, and thence the car is runinto the kiln K upon one or another of the tracks K shown clearly in Fi2 of the drawings. After the cakes of lime ave been thoroughly driedwithin the drying kiln, the cars containing the cakes are moved out uponone or another of the tracks L leading from the op osite end of thekiln, as shown in Fig.- l of t e drawings, and upon thetransanti-friction rollers, not shown, said kiln bevvenientl ing rotatedreferahly by the gear wheels S and S whic latter through the shaft S andpinion wheel S drive the gear wheel 8 fixed to the rotary kiln. Saidgear mechanism may be driven from any source of supply, as from' anengine designatedby S Located adjacentto one end of the rotary kiln is agas producer T in whfih coal or other gaseous fuel is reduced to gaswhich is carried throu h a flue T, and through the hood T", into t ekiln S where it is burned. Said kiln is provided with abrick lining,designated in the drawings by T and certain of said brick preferablyproject beyond others for the purpose of a 'itating the pieces of limecake as they slow y travel through the rotary kiln, it being understoodthat the kiln is disposed prefer- ;ably at a slight inclination in orderthat the lime materia may be fed by gravity throu h the same; Theburning as heats up t e fire brick lining to a high egree of tem era-'ture and the interior of the rotary kiln eing heated to the properpoint, the crushed lime cake traveling slowly through the kiln willabsorb the heat from the burning gas and the heated brick lining untilit reaches the burning zone where it ives ofi'its CG, and becomesreduced to t e oxid state. The lime is then discharged from the kilnthrough the hood 'i underneath which is positioneda suitable conve er Twhereby the lime material is carrie to an elevator T which conveys thematerial to and discharges the same into the tanks W; V I have foundfrom extensive experimenting that arr-essential step in my'improvedprocess for revivifyinglspent lime consists in the granulation of t ecakes, which have been dried and passing the ranules in a carbonate formthrough the ki where the calcining takes lace. l have alsodemonstratedthat, w erelthe lime to be dried or calcined is of a looseform when it passes into a kiln, it is not possible to successfully burnthe same, as it appears to be necessary that the lime when beingcalcined be in a dense, solid form. To secure the best results, thegranules should be of such a size as might conpass through a screen of aone inch mesh, a t ough granules of slightly larger size can besuccessfully calcined.

The highly heated Cl), gas, which is pro duced by t e calcining of thewaste carbonate of lime material, is drawn through the kiln S, thencethrough the nipple V into the'dust separation chamber X, the stack Xbeing utilized to produce a draft from the dust chamber X, whereby theCt), gases may be draw/n into a water heater 5, preferably of thestandard fuel economizer type, through the inlet 6 which communicatesbebetween the water heater and the dust chamber. .The water contained inthe pipes 7 of said heater absorbs a'portionof the heat in the CO,gases, after which the C0 gases are drawn through an air heater 8, whichis composed of a series of air pipes 9, through which pure air is eitherforced or drawn through the air duct 10 by means of the fan 11, andabsorbs heat from the CO, gases and is then discharged by the fanthrough the duct12 into the interiorof the drying chamber K through thebranching ducts 13, shown in Fig. 1 of the drawings. The heated gasesthus being introduced into the drying chamber or kiln come in contactwith the cakes in a wet state upon the car and will take up the moisturefrom the wet cakes, which moisture is drawn out of the drying chamberthrough the stack A The I C0 after having imparted nearly all of itsheat, first heating up the lime materialas it travels toward the burningzone in theukiln,

kiln after passing through the water heater,

or, if desired to dry the'lime at a high temperature, the C0, gas may beintroduced (direct into the drying kiln as it comes from the dustchamber X.

' From the foregoing, it will be noted that. the lime which has beenreduced to carbonate form, by serving its urpose chemical or otherwise,and which ime, after having served its purpose in the wild form andreduced to carbonate state and in which carbonate state it has hithertobeen considered waste material, may be reclaimed at low cost and againused at commercial value.

While l have described my process as being utilized especially inconnection with the reclaiming of waste lime, it will be understood thatthe same steps may be carried out in preparing and calcining marl, whichis usually nearly all pure carbonate of lime, but which in its usualdeposit form contains a high percentage of water" and, by the treatingof-th arl in the filter press, drier and rotary kil the marl depositsmay be utilized by first extracting the water as outlined in my processand then reducing the carbonateoi lime in an oxid state in the rotarykiln the same manner as in recovering waste lime.

'What I claim is 1- 1. The process of purifying and revivifying s cut orwaste lime consisting in reducing 1; esame to a solid form, afterwarddrying the carbonate of lime in a solid form, and coarsely granulatingthe lime and reducing it by heat to an oxid state, as set forth.

1 form, afterward drying the carbonate of ing spent or waste limeconsisting in reducing t e same to a solid form, afterward drying thecarbonate of lime in a solid form by air hi hly heated by C0 gas, thencoarsely granu ating the lime and reducing it by heat to an oxid state,as set forth.

3. The process of purifying and revivifying spent or waste imeconsisting in first separating impurities therefrom, reducing the limeto a solid form, afterward drying the carbonate of lime in a solid form,then' coarsely granulating the lime and reducing it by heat to an oxidstate, as set forth.

4. The process of purifying and revivifying spent or waste imeconsisting in first separating impurities therefrom, relieving thepurified lime of a lar e percentage of its water, reducing it to a so idform, afterward drying the carbonate of lime in a solid form, thencoarsely granulating the same and reducing it by heat to an oxid state,as set forth.

5. The process of purifying and revivifying-spent or waste imeconsisting in first separating impurities therefrom, relieving thepurified lime of a lar e percentage of its water, reduc-in it to a solidform, afterward drying the car onate of lime in a solid form by airhighly heated by C0 gas, then coarsely granulating the lime and reducingit by heat to an oxid state, as set forth.

6. The process of urifying and revivifying spent or waste ime consistingin first se arating the impurities therefrom by centrifugal force,reducing the lime to a solid lime in a solid form, coarsely granulatingthe same and reducing it by heatto an oxid state, as set forth.

7. The process of purifying and revivifying spent or waste imeconsisting in first separating the im urities therefrom by centrifugalforce, re ucing the lime to a solid form, afterward drying the carbonateof lime in a solid form, by air highly heated by 1 CO gas, and thencoarsely granulating the lime and reducing it by heat to an oxid state,as set forth.

8. The process of urifying and revivifying spent or waste ime consistingin first separating the impurities therefrom by cen trifugal force,relieving the purifiedlime of a large percenta e of its Water, reducingthe lime to a soli form, afterward drying the carbonate of lime in asolid form by air highly heated by C0 gas, then coarsely granulating thelime and reducing it by heat to an oxid state, as set forth.

9. The process of purifying and revivifying spent or waste limeconsisting in separating t 1e impurities therefrom when in a semiliquidstate, reducing the lime to a solid form, afterward drying the carbonateof lime in a solid form, then coarsely granulat-' ing the same andreducing it by heat to an oxid state, as set forth.

10. The process of purifying and revivifying s ent or waste lime consiting n separating t re impurities therefrom when in a semiliquid stateby centrifugal force, reducing the lime to a solid form, afterwarddrying the carbonate of lime in a solid form by air highly heated by C0gas, and then coarsely granulating the lime and reducing it by heat toan oxid state, as set forth.

11. The process of purifying and revivif v ing spent or waste limeconsisting in separat: ing the impurities therefrom when in a semiliquidstate by centrifugal force. relieving the purified lime of a largepercentage of its water, reducing the lime to a solid state, afterwarddrying the carbonate of lime in a solid form by air hi hly heated by C0gas, then coarsely graiiiifating the lime and reducing it by heat to anoxid state, as set forth.

12. The process of purifying and revivifying spent or waste limeconsisting in first separating impurities therefrom, mixing the limewith water, thoroughly agitating the same, afterward relieving the limeof a large percentage of the Water, drying the carbon ate of lime in asolid form, then coarsely granulating and reducing it by heat to an oxidstate, as set forth.

13. The process of purifying and revivifying spent or waste limeconsisting in first separating im urities therefrom, reducing the limeto a so id form, drying the same in a solid form by air heated by (0,gas issuing from a kiln, the temperature of the gas being reduced by itsbeing passed through water and air heaters, then reducing the lime to acoarsely granulated condition, and afterward calcining the latter in ahighly heated kiln and reducing it to an oxid state, as set forth.

In testimony whereof I hereunto allix my signature in the presence oftwo witnesses.

JOHN G. JONES.

Witnesses:

A. T. Woon, PETER YONSEY.

